package com.lhl.forum.interceptor;

import com.lhl.forum.config.AppConfig;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * 登录拦截器
 */

@Component
public class LoginInterceptor implements HandlerInterceptor {

    @Value("${lhl-forum.login.url}")
    private String defaultUrl;

    /***
     * 前置处理
     * @return true 继续流程 <br/>  false 流程中断
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        //获取session
        HttpSession session = request.getSession(false);
        //判断session是否存在
        if (session != null && session.getAttribute(AppConfig.USER_SESSION) != null){
            //用户已经登陆
            return true;
        }

        //校验URL是否正确
        if (!defaultUrl.startsWith("/")){
            defaultUrl = "/" + defaultUrl;
        }

        //校验不通过，跳转到登录页面
        response.sendRedirect(defaultUrl);

        return false;


    }
}
